Joseph m



J. M. LAUGHLIN. Manufacture of Horseshoe Nail Plates.

No. 233,357. Patented Oct. 19, 1880.

ILPETERS, FNOTO-LITHOGRAPHERrWASHlNGTON, D C.

UNITED STATES PATENT OFFIcE,

JOSEPH M. LAUGHLIN, OF BRIDGEWATER, MASSACHUSETTS, ASSIGNOR TOBRIDGEWATER IRON COMPANY, OF SAME PLACE.

MANUFACTURE OF HORSESHOE-NAIL PLATES.

SPECIFICATION forming part of Letters Patent No. 233,357, dated. October19, 1880.

Application filed July 8, 1878.

To all whom it may concern:

Be it known that I, J osEPH M. LAUGHLIN, of Bridgewater, in the countyof Plymouth and State of Massachusetts, have invented certain new anduseful Improvements in the Manufacture of Horseshoe-Nail Plates, ofwhich the following is a description.

Myim'ention relates to the plates from which horseshoe-nails are to bemanufactured by a machine substantially similar to that shown in myLetters Patent No. 189,108, dated April 3, 1877; and it consists inputting such a finish upon the surface of the plate that when it is cutinto horseshoe-nails by said machine such nails will be substantiallyperfect and ready for the market Without applying any other finishingprocess thereto.

H eretofore the process of cold-rolling horseshoe-nail plates on certainparts of the plates has been resorted to for the purpose of hardenin gor condensing the material of the plate in those parts of it which areto form the pointed end of the nail and the shank immediately adjacentthereto, as is described in the patent of Harrington, No. 159,410; butit was not known that such cold-rolling could be applied to the parts ofthe nail-plate which are to produce the head and softer part of theshank of the nail without materially injuring the softness of the metalwhen such cold-rollin g was applied with sufficient pressure to finishthe surface of the nail-plate; and hence, when horseshoe-nails have beenpunched from such a nail-plate previous to my invention, it has beenfound necessary to finish the heads and adjacent portions of theseparated nails by stamping, pressing, or grinding and polishing themseparately, which proves to be an expensive and tedious process. Besidesthis, the cold-rolling of the nail-plates as described by Harringtoncould never produce a finished horseshoe-n ail plate such as myinventiondoes, because Harrington rolls his plate with a pressure of greatintensity at the central and thinnest part of the plate longitudinallyand a diminished pressure toward the thicker edges of the plate, as hedescribes. The effect of thus rolling the plate is to not only expandthe plate sidewise, but also to increase its length at the central partof the plate in a greater degree than toward the edges, which are notcoldrolled under such pressure. This causes the nail-plate to curl orbuckle all along its surface from just within the edges, and makes itssurface rough and corrugated and unfit for the surface of a finishedhorseshoenail without further manipulation. Hence the cold-rolling ofthe plate as described by Harrington produces just the opposite effectfrom that effected by it when applied by my method.

My invention consists in the discovery that a certain amount of pressuremay be applied to the rolls used in cold-rolling nail-plates ofhomogeneousiron upon the parts of such plates from which the heads andadjacent shank parts of the nails are to be formed, sufficient to give asmooth and perfect finish to the surface of the plate suitable for thenails, without at the same time so compressing and hardening these partsof the metal in the nail-plate as to injure the head and shank part ofthe nail, which are required to be left soft and pliable for effi cientuse; and, further, in producing by this method of cold-rolling a finishupon nail-plates in those parts intended to form the head and soft shankof the completed nail without ma-v teriallyinjuring their softandpliablecondition.

By means of this improvement I am able to produce a cheap and perfectfinish upon all parts of the nail-plate without impairing its value forthe purpose of forming horseshoenails, because, the point of the nailand its adjacent parts being finished and hardened by a rolling processlike that of Harrington, or the cold-stampin g process set forth in mypatent of November 7, 1876, and the remainder of the surface of thenail-plate being finished by my present invention or discovery, thehorseshoe-nails may be punched therefrom by my machine, as firstmentioned, without any further preparation, and when the horseshoenailsare punched from my improved plate they require no further process ofstamping, pressing, or polishing upon the heads or adjacent shank part,but are ready to be immediately packed for the market.

In the drawings, Figure 1 represents a plan or top view of a section ofthe plate having some of the nails punched therefrom. Fig. 2 representsan end view of the same. Fig. 3

represents a plate of double width.

A A represent the ribs on the plate, which form the heads of thenailswhen out therefrom, and B B is the central portion of the'plate whichforms the shanks of the nails. This plate is of homogeneous iron, and inorder to produce the finish upon it by my process of cold-rollingwithout injuring the softness and pliability of the iron it is necessaryto take it, after it has been reduced to shape by hot-rolling and beforeit is subjected to the cold-rolling process of Harrington orcold-stamping process of my own, as above mentioned, to pass it througha pair of rolls whose configurations correspond, respectively, to theopposite sides of the plate, the pressure of such rolls upon the platebeing carefully adjusted to the degree which will produce asubstantially smooth and perfect finish upon both surfaces of the platewithout such pressure being much greater than is absolutely requisite toproduce such finish.

Should the pressure upon the finishing-rolls be greater than isnecessary substantially, it may be readily discovered by testing one ormore of the nails produced from such plate, for in that case the shankof the nail at, say, one-third of the distance or more from its pointwill be found to have lost its soft and pliable condition in a materialdegree, which is its chief value. it, however, the pressure of thefinishing-rolls be adjusted properly, the value of the nails, as abovedescribed, will not be perceptibly impaired, and a suitable finish willhe at the same time produced upon the nail-plate.

From this description the practical operator can readily determine howto adjust his finishing-rolls, and although the adjustinent must be madewithin somewhat narrow limits, by observing due care it can beaccomplished without great diffieulty. It is necessary to perform thisfinishing process upon the head and shank parts of the nail-plate at aseparate operation from the hardening process by cold rolling ofHarrington or from the hardening process by cold-stamping of myself,before referred to, for forming the parts of the plate intended for thepoints of the nails and the parts immediately adjacent thereto, becausewhile compressing the metal to harden it by one part of the roll orstamper it is not possible, so far as I have discovered, to graduate thepressure of the instrument so as to produce a finish upon the otherparts of the plate without injuring the softness and pliability of theirmetal materially.

I do not claim the art of cold-rolling metal generally, nor the samehowever it may be applied to horse-nail plates; but

What I claim as new and of my invention 1. As a new article ofmanufacture, a horse shoe-nail plate of proper form for producing thecompleted nails therefrom, and having its parts which are designed toproduce the head and adjacent shank parts of the nail finished bycold-rolling uniformly without material injury to the softness andpliability of the metal therefor, substantially as described.

2. The described process of finishing horseshoe-nail plates bycold-rolling the same uniformly with a pressure graduated to produce afinish upon their surfaces withoutimpairing materially the requisitesoftness and pliability of the metal thereof, substantially asdescribed.

JOSEPH M. LAUGHLIN.

Witnesses CHARLES Enn PRATT, A. K. GARLAND.

